The candidate was an academic star who talked economics with Milton Friedman, worked and studied long hours, and successfully planned his future as a businessman and philanthropist.

A constant I’ve found in writing profiles and biographies is that college has been a pivotal experience in most of my subjects’ lives: the University of Illinois for Roger Ebert; the University of Chicago for Katharine Graham; Princeton for Don Rumsfeld and (in a negative way) for Michelle Obama; Northwestern for Rod Blagojevich.

This held true as I did the legwork for a profile of Bruce Rauner for this magazine. Dartmouth College, which he attended between 1974-78, was definitely defining for the Republican gubernatorial candidate. As Rauner approaches his 60s, many of his closest friends are guys he met in college.

Rauner spent a year at Lake Forest High School before moving to Saguaro High in Scottsdale, when Motorola transferred his father to Phoenix. Both parents were University of Michigan grads, so Rauner had no legacy status at the Ivy League school in Hanover, New Hampshire. He got in on his merits, and the college, which has benefited from Rauner’s largesse—$850,000 since 2009; his name on a residence hall and on the Rauner Special Collections Library—surely must have no regrets about admitting the eldest of four siblings. And not just because of Rauner’s generosity to his alma mater, but because he graduated summa cum laude and Phi Beta Kappa and went on to an extremely successful career in business. Should he be elected on November 4, he’ll be the first Dartmouth grad to become governor of Illinois. (In a weird coincidence, CTU president and potential Rahm challenger Karen Lewis could be the first Dartmouth grad (’74) to become mayor of Chicago.)

Here’s some facts about Rauner and Dartmouth that provide a window into the candidate’s character:

It was at Dartmouth that Rauner found the subject of economics. He took a class from Colin Campbell, a revered Dartmouth professor, who had studied with Milton Friedman at the University of Chicago. Prof. Campbell so inspired young Rauner that he decided that he should use his education to go into business, make a lot of money and give to the causes he cared about—the environment and education. He has totally fulfilled that pledge he made to himself almost 40 years ago. “He had a theory,” says Rauner’s frat brother Andy Ebbott, “that rather than going to work for the Peace Corps, that once you have the resources, you help out a higher level.”

Classmates describe Rauner as so smart he would help them with their work, without ever losing patience with their questions or making them feel inferior for asking them. “Bruce was super smart, sharply competitive, took advantage of every opportunity,” says classmate Steve Kaiser, who was from Freeport. “He was smarter than I was; I would usually go to him for help.” Dave Casper, who grew up in Milwaukee, now lives in Northbrook, and is the number two at BMO Harris, recalls that Rauner “wouldn’t show he was so smart but he knew he was. I was taking basic courses; he was taking advanced everything, including physics and calculus.”

Milton Friedman and his wife Rose had a summer home close by the Dartmouth campus, and, says Casper, who was Rauner’s freshman and sophomore year roommate and today one of his closest friends, Bruce would mix it up with the 1976 Nobel Prize in economics winner who would come to campus to speak to the “way, way advanced classes… Bruce could engage with Friedman in a way others couldn’t… Friedman was a driving force with Bruce.”

Rauner has shown himself to be a tireless campaigner, as he has shown himself to be exceedingly energetic when he worked at GTCR and in his volunteer efforts at school reform. At Dartmouth, that work ethic was already evident. Animal House, which portrayed Dartmouth as a drunken frat boy’s dream school, was released in 1978, the year Rauner graduated, but that wasn’t Rauner’s Dartmouth. He joined Theta Delta Chi, known as a jock house—not the house lampooned in the movie—but, says Casper, “worked his ass off. He wrote a thesis and worked on it 24/7, killed himself working on it. “He loved the outdoors, but carefully budgeted his time. He skied and snow-shoed when he wasn’t studying, but mostly he studied.”

His friends recall him as shy, “quieter than most,” says Casper, not necessarily cut out to be a CEO. Steve Kaiser, who now lives in Rockford, explains that even if becoming a corporate CEO was Rauner’s goal at the time, he didn’t have the right pedigree, the right prep school or a III or IV next to his name. “Being from Freeport… I tended not to want to be around those sorts. I liked Bruce because he was a sincere, good guy, not full of himself.” His friends were mostly Midwesterners. His Dartmouth classmate Jeffrey Immelt, who came from Cincinnati, currently chairman of GE, recalls Rauner as not so much shy as “serious.” Bruce had three main qualities, says Immelt, who overlapped with Rauner at Harvard Business School and has contributed to his campaign, “he was serious, smart, valued friendship and was very loyal to his friends.”

Rauner showed no interest in politics while in college. “I can tell you,” says Dave Casper, “when I first met Bruce, the first thing that popped into my head was not, ‘There goes the next governor of Illinois.’”

“Politics wasn’t a topic of conversation,” says Kaiser. “We talked more about monetary and fiscal policy.”

Rauner’s family was upper-middle-class, but his father, Vince, was “tight” with money, so Bruce had a series of jobs at Dartmouth. He had a deep voice, and that got him a job as an announcer at the college station, WDCR. “That deep voice comes from his toes,” says Kaiser. He covered mostly news and sports and his friends would rib him that he had “a great radio face.” He worked also at the dining hall, often very late and early. “He was the grill guy and flipped burgers,” says Kaiser. Casper recalls him making and flipping German French toast for breakfast.

Bruce and frat brother Andy Ebbott, who was from Minnesota, went to Palm Beach during an off term to work at the Breakers. (A Dartmouth alum ran the hotel’s human resources department.) Rauner worked as a waiter. “I did not get that high a job,” says Ebbott. “We were told to arrive before Christmas. The ones who got down early got the good jobs. The ones who got there later got the leftovers. I wanted to spend Christmas with my family.”

None of his friends recall ever seeing Bruce’s family on campus. “I never met any of them,” says Steve Kaiser, adding, “I don’t really remember his talking about family too much.” Dave Casper says he met Bruce’s siblings years later at Vince Rauner’s funeral. Bruce was the only one of his sibs to go to Dartmouth. “Bruce is the star of the family,” says Casper.

At Dartmouth and later at Harvard Business School, Bruce drove a purple-colored, beat-up Chevy Nova. (If he still owned it, it would, undoubtedly, pop up in a campaign ad.) Friends joke that the car started out red but turned purple with age and use. During school vacations, Rauner would drive Kaiser to Illinois, Casper to Wisconsin, and then drive on alone to Arizona. He enjoyed driving and wouldn’t give up the wheel to anyone else. He also wouldn’t stop at motels; he would drive “straight through,” says Casper. He relished spending time with Kaiser’s family and “got a kick” out of the fact that they ate dinner together every night. He was also close to Casper’s family. “My family loved Bruce,” says Casper. “My sister had a crush on him… Bruce showed up a day early one time. I wasn’t home and my mom asked him if he wanted an omelet and how many eggs. ‘How many can you afford?’”

During school vacations the friends went river canoeing in northern Minnesota. (Canoeing was then Rauner’s favorite outdoor sport.) One time, says Kaiser, “we got in over our heads, a white water river, and we were not white water skilled, destroyed our canoes. We all just bounced off the rocks. Lost all of our gear, lost our shoes.” After graduation, in the summer of 1978, Ebbott, Rauner, and a couple of others, traveled to Alaska. They pooled their money and bought a Jeep Wagoner, camped and fished, then handed the Jeep off to a fraternity brother to sell when it was time to go home, to get moving on their adult lives.

Carol Felsenthal is a lifelong Chicagoan and self-proclaimed political junkie. She writes occasionally for Politico Magazine and The Hill. Her books include biographies of Bill Clinton, Katharine Graham, and Alice Roosevelt Longworth. Among her many stories for Chicago are memorable profiles of Michelle Obama and Bruce Rauner. Follow her on Twitter at @csfelsenthal.